This proposal sets out a framework to study the cognitive mechanisms underlying the relationship between changes in attention and memory declines in healthy older adults. The primary hypothesis is that aging affects the operation of processes involved in the formation of excitatory and inhibitory connections between verbal concepts, connections which serve to create integrated representations while simultaneously keeping concepts distinct from each other and from prior knowledge. Three main predictions are tested: (1) Aging reduces the strength of excitatory connections formed between individual words contained in verbal input; (2) Older adults are less able to suppress irrelevant input than younger adults; and (3) Age differences occur in the ability to segregate input from prior semantic knowledge, when the input conflicts with, or is difficult to discriminate from that prior knowledge. Each of the eight experiments involves the presentation of verbal stimuli (individual words, word pairs, or sentences) followed by a memory test (free recall, cued recall, or recognition memory). All involve comparisons between young, middle-aged, and older adults. In addition, a subset of the experiments will be administered to patients with anterograde amnesia. Because attention is believed to affect memory functioning only in the healthy aging group, the amnesic population will provide an important comparison group.